S5-115F Manual
Communications Capabilities
Transfer of error DBs
Please note the following when programming your SINEC L1 messages:
If a subunit detects a 115F error, the subunit sends the body its error DB (56 bytes) to the SINEC L1
master. In such a case, subunit A sends DB 2 and subunit B sends DB 3. The frame received by the
master contains a frame header as well as the actual body of the error DB. The structure of the
frame header depends on the type of networking. A distinction is made between:
•
Point-to-point connection between an S5-115F as slave and an S5-95U with two interfaces or
S5-115U with the CPU 943 or CPU 944 as master. The link is possible via the programmer
interface with or without SINEC L1 BT 777 transceivers.
•
Connection between several S5-115Fs as slaves and an S5 of the U range with CP 530 as master.
The user program differentiates between error message frames from the operating system and all
other frames in the following way in the case of both types of connection:
•
Error message frames always have a 56-byte long body. The length of the body is given in the
frame header.
•
The second byte of the frame body contains the subunit ID of the source
- in the case of one-channel SINEC L1 LAN:
second byte = ”B”
- in the case of two-channel SINEC L1 LAN in the master of LAN A:
second byte = ”A”
- in the case of two-channel SINEC L1 LAN in the master of LAN B:
second byte = ”B”
So that your user programs are not mistaken for error message frames by the operating system, all
user message frames which
•
have a frame body length of 56 bytes
and also
•
have ID ”A” or ”B” in the second byte of the frame body
are prohibited:
The following two figures show the different structure of both Receive message frames in the
master PLC.
In the case of point-to-point connection, the Receive mailbox of the master contains the following
frame:
Length of message body (bytes) = 56
Slave No. of source S5-115F
2
3
4
:
:
:
56
57
Message header
Byte
0
1
Message frame body of
the error message
(error DB body)
Unassigned
58
:
:
:
:
:
65
'C' = B
(or A or B in the case of a two-channel SINEC L1 LAN)
Figure 7-7.
SINEC L1 Message Frame with Error Message in the Case of Point-to-Point Connection
EWA 4NEB 811 6148-02
7-11